Action of Varespladib (LY-315920), a Phospholipase A2 Inhibitor, on the Enzymatic, Coagulant and Haemorrhagic Activities of Lachesis muta rhombeata (South-American Bushmaster) Venom

Varespladib (VPL) was primarily developed to treat inflammatory disturbances associated with high levels of serum phospholipase A2 (PLA2). VPL has also demonstrated to be a potential antivenom support agent to prevent PLA2-dependent effects produced by snake venoms. In this study, we examined the action of VPL on the coagulant, haemorrhagic and enzymatic activities of Lachesis muta rhombeata (South-American bushmaster) venom. Conventional colorimetric enzymatic assays were performed for PLA2, caseinolytic and esterasic activities; in vitro coagulant activities for prothrombin time (PT) and activated partial thromboplastin time (aPTT) were performed in rat citrated plasma through a quick timer coagulometer, whereas the dimensions of haemorrhagic haloes obtained after i.d. injections of venom in Wistar rats were determined using ImageJ software. Venom (1 mg/ml) exhibited accentuated enzymatic activities for proteases and PLA2in vitro, with VPL abolishing the PLA2 activity from 0.01 mM; VPL did not affect caseinolytic and esterasic activities at any tested concentrations (0.001–1 mM). In rat citrated plasma in vitro, VPL (1 mM) alone efficiently prevented the venom (1 mg/ml)-induced procoagulant disorder associated to extrinsic (PT) pathway, whereas its association with a commercial antivenom successfully prevented changes in both intrinsic (aPTT) and extrinsic (PT) pathways; commercial antivenom by itself failed to avoid the procoagulant disorders by this venom. Venom (0.5 mg/kg)-induced hemorrhagic activity was slightly reduced by VPL (1 mM) alone or combined with antivenom (antivenom:venom ratio 1:3 ‘v/w’) in rats, with antivenom alone producing no protective action on this parameter. In conclusion, VPL does not inhibit other major enzymatic groups of L. m. rhombeata venom, with its high PLA2 antagonize activity efficaciously preventing the venom-induced coagulation disturbances.

Hybrid Surface Characterisation of Intra Thin-Walled Ti6Al4V Surfaces Produced by Laser Powder Bed Fusion Technology

The proposed work investigates the hybrid surface characterisation of intra thin-walled Ti6Al4V surfaces fabricated using laser powder bed fusion technology. The thin-walled samples were characterised using scanning electron microscopy and Opto-digital microscopy techniques. The fractal dimensional analysis was performed using ImageJ software integrated with an open-source MultiFrac plug-in. The surface microscopy analysis revealed satellites powder particles, partially melted powder particles, spherical balling, and pores on the thin-walled surface. The fractal dimension establishes a correlation between the surface roughness values. The surface areal surface parameters analysis suggested variation along the build direction of thin-walled Ti6Al4V sample. The development of sharp peaks and thus higher Ra, Sku and Ssk values were found along the build direction of the intra thin-walled samples. Therefore, the combination of areal surface topography analysis and fractal dimension approach can be a promising methodology towards surface characterisation of additively manufactured complex thin-walled surfaces.

Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues

Background This study aimed to investigate the effect of automatic exposure compensation (AEC) of intraoral radiographic systems on the gray values of dental tissues in images acquired with or without high-density material in the exposed region using different exposure times and kilovoltages. The influence of the distance of the high-density material was also investigated. Methods Radiographs from the molar region of two mandibles were obtained using the RVG 6100 and the Express systems, operating at 60 and 70 kV and 0.06, 0.10, and 0.16 s. Subsequently, a titanium implant was inserted in the premolar’s socket and other images were acquired. Using the ImageJ software, two regions of interest were determined on the enamel, coronary dentine, root dentine, and pulp of the first and second molars to obtain their gray values. Results In the RVG 6100, the implant did not affect the gray values (p > 0.05); the increase in kV decreased it in all tissues (p < 0.05), and the exposure time affected only the root dentine and pulp. In the Express, only enamel and coronary dentine values changed (p < 0.05), decreasing with the implant presence and/or with the increase in exposure factors. The distance of the implant did not affect the results (p > 0.05). Conclusions AEC’s performance varies between the radiographic systems. Its effect on the gray values depends not only on the presence or absence of high-density material but also on the kV and exposure time used.

ВПЛИВ МЕХАНІЧНОЇ АКТИВАЦІЇ НА РОЗМІРНІ ХАРАКТЕРИСТИКИ ТА ФОРМУ ЧАСТИНОК ГЛИНОПОРОШКІВ РІЗНОГО ТИПУ

Purpose. Determination of the influence of the process of preliminary mechanical activation on the dimensional characteristics and shape of particles of different types of clay powders.Methodology. Clay powders of montmorillonite and palygorskite type were chosen as the objects of research in this work. The process of mechanical activation of clay powders was carried out using a laboratory ball mill. For microanalysis of sample particles, the method of optical polarizing microscopy was used. Morphometric analysis of clay powder particles was performed by image analysis using the ImageJ software. At the same time, the area and perimeter were determined, and the equivalent diameter and also the shape index of the particles of the samples were calculated. The experimental data were statistically processed using the Statistica and Excel software packages.Results. The paper investigates the effect of the process of mechanical activation on the dimensional characteristics and shape of particles of montmorillonite and palygorskite type clay powders. It was found that the decrease in the average values of the equivalent particle diameter in the process of mechanical action (~14–15%) is realized mainly due to the destruction of their largest aggregates. Moreover, the intensity of this process is noticeably higher for clay of the montmorillonite type. It is shown that for both studied samples, the process of mechanical activation leads to an increase in the average values of the particle shape index (~ by 9–10%) and an increase in the uniformity of their distribution by this index.Scientific novelty. Using a detailed morphometric analysis of particles of various types of clay powders, the regularities of the influence of the mechanical activation process on the quantitative statistical characteristics of their distribution over the equivalent diameter and shape index have been established.Practical value. The results obtained will make it possible to reasonably approach the choice of pretreatment methods for clay powders intended for the production of polymer filled nanocomposite materials.

A Comparison of Ultrasound Echo Intensity to MRI as a Metric for Tongue Fat Evaluation

Study Objectives Tongue fat is associated with obstructive sleep apnea (OSA). Magnetic resonance imaging (MRI) is the standard for quantifying tongue fat. Ultrasound echo intensity has been shown to correlate to fat content in skeletal muscles but has yet to be studied in the tongue. The objective of this study is to evaluate the relationship between ultrasound echo intensity and tongue fat. Methods Ultrasound coronal cross-sections of ex-vivo cow tongues were recorded at baseline and following three 1 milliliter serial injections of fat into the tongue. In humans, adults with and without OSA had submental ultrasound coronal cross-sections of their posterior tongue. Average echo intensity of the tongues (cow/human) were calculated in ImageJ software. Head and neck MRI were obtained on human subjects to quantify tongue fat volume. Echo intensity was compared to injected fat volume or MRI derived tongue fat percentage. Results Echo intensity in cow tongues showed a positive correlation to injected fat volume (rho = 0.93, p&lt;0.001). In human subjects, echo intensity of the tongue base strongly correlated with MRI-calculated fat percentage for both the posterior tongue (rho = 0.95, p&lt;0.001) and entire tongue (rho = 0.62, p&lt;0.001). Larger tongue fat percentages (rho = 0.38, p=0.001) and higher echo intensity (rho = 0.27, p=0.024) were associated with more severe apnea-hypopnea index, adjusted for age, BMI, sex and race. Conclusions Ultrasound echo intensity is a viable surrogate measure for tongue fat volume and may provide a convenient modality to characterize tongue fat in OSA.

Features of angioarchitectonics and structure of the aortic wall of white rats in the early stages of experimental diabetes mellitus

Background. Atherosclerotic cardiovascular diseases, as well as coronary heart disease, cerebrovascular disease, and peripheral artery disease (probably caused by atherosclerosis), are the leading cause of disability and mortality in people with diabetes. Objective. The purpose of our study was to determine the histostructural features and morphometric analysis of the components of the aortic wall and its hemomicrocirculatory bed after 2 and 4 weeks of streptozotocin-induced diabetes mellitus. Methods. The samples for the histology were the sections of the wall of the ascending part, the aortic arch, and the descending part of the aorta of 26 mature white male rats weighing 100 - 160 g. For morphometric examination, a series of images of the aortic wall was taken using a Meiji MT4300 LED microscope with an x40 objective, x10 eyepiece. Results and conclusion. The measurements were carried out using the ImageJ software. The development of micro- and macroangiopathies in experimental animals with 8-week streptozotocin-induced diabetes mellitus was histologically proved. Statistical analysis revealed a significant difference of all morphometric parameters of both - the components of the aortic wall and the vessels of its hemomicrocirculatory bed after 4 weeks of experimental diabetes in comparison with the norm, control, and the 2-nd week of the experiment. An explicit dependency of the severity of destructive changes in the wall of the aorta and links of its hemomicrocirculatory bed of vessels on the duration of the experiment was determined.

Application of ImageJ Software in the assessment of flowering Intensity and growth Vigor of pear Trees

The study evaluated the possibility of using the image acquisition and processing method with ImageJ software for estimating growth vigor and flowering intensity of ‘Conference’ pear trees. For assessing flowering intensity, manual counting of flower clusters and taking of photographs of the trees were conducted at full bloom. Tree vigor was estimated by manually measuring the total length of the central leader and shoots of individual trees. The trees were photographed from the same distance using a hand-held camera. The calibration model for assessing the vigor or flowering of trees by image analysis was based on measurements and photographs taken for nine selected trees differing in the total length of shoots or in the number of flower clusters. Then, a quality assessment of the model was carried out on 26 nonselected trees. Image processing was performed using ImageJ software. High regression coefficients were obtained between the surface area of petals measured on the photographs and the number of inflorescences counted (r2 = 0.98); however, observations carried out in the following year indicate the need for individual calibration of estimation models in each evaluation season. Subsequently, the quality of estimating the flowering intensity of pear trees was assessed using a previously determined calibration model. Mean absolute percentage error (MAPE) values ranged from 14.0% to 21.8%, depending on the measurement time. In the assessment of tree growth vigor, a high correlation (r2 = 0.98) was also obtained between the actual length of shoots measured individually for each tree and the values obtained by analyzing the photographic image, where the MAPE error was 12.9%.

Evaluation of photocatalytic activity of titanosilicate powders of synthetic origin

In this work, a comparative study of the photocatalytic activity of synthetic titanosilicate powders with differences in phase composition and specific surface area was carried out. Evaluation of the efficiency of decomposition of the dye methylene blue in the presence of titanosilicate additives in an aqueous medium under ultraviolet and visible light sources is given. The self-cleaning ability of titanosilicate-modified cement stone was studied by exposure to ultraviolet and visible light using ImageJ software. The strength of a cement stone modified with a titanosilicate additive has been determined, and its ability to self-cleaning under the influence of ultraviolet and visible light has been studied.

Rigid and film bioplastics degradation under suboptimal composting conditions: A kinetic study

The present research investigates the degradation rate of bioplastics under various composting conditions, including suboptimal ones. Lab-scale tests were carried out setting three variables: temperature (37°C–58°C), humidity (30%–60%) and duration of the thermophilic and the maturation phases (15–60 days). The composting tests were carried out following modified guideline ISO 20200:2015 and lasted for 60 days. Bioplastics in the synthetic waste matrix consisted of Mater-Bi® film biobags and PLA rigid teaspoons. A kinetic study was performed, resulting in faster degradation rates for film bioplastics (first-order kinetics with k = 0.0850–0.1663 d−1) than for rigid (0.0018–0.0136 d−1). Moreover, film bioplastics reached a complete degradation within the 60 days of the test. Concerning the rigid products, 90% degradation would be achieved in 2–3 years for mesophilic conditions. Finally, in the undersieve of 0.5 mm some microplastics were identified with the ImageJ software, mainly relatable to rigid (PLA) bioplastics. Overall, the results disclosed that the combination of mesophilic temperatures and absence of moistening slowed down both the degradation and the disintegration process of bioplastics.